Mast-arm for electric lamps



(No Model.)

T. B. KEELER.

MAST ARM FUR ELECTRIC LAMPS.

N0. 355,400. Patented Jan. 4,]188'7.

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N PETERS Hwm-Limo n hur. Washinglun. D. c.

. cred position; Fig. 2, a rear view of the top w ance to the-lamp.

' NITED STATES PATENT Erica.

- MAST-ARM FOR ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 355, 400, dated January 4, 1887.

Serial No. 199,746. (No model.)

To all whom it may concern.-

Be it known that I, THADDEUS B. KEELER, a citizen of the United States, residing at Danbury, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Mast-Arms for Electric Lamps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to produce a device which will enable electric lamps to be lowered when-it is desired to clean them or to renew the carbons, and by which they may be readily restored to position for use.

In carrying out my invention I so balance the parts that the lamp is retained in either its raised or lowered position without other devices. I thus avoid any special or severe strain upon the cords which sustain the lamp. I have, furthermore, provided a special device which will'catch the lamp and prevent its falling in the event of the breaking of either or both of the cords when the lamp is in its raised position. These results I am enabled to accomplish by means of the novel construction and arrangement of parts, of which the following description, in connection with the accompanying drawings, is a specification, numbers being used to indicate the several parts of the device.

Figure 1 isa side elevation of the device complete, the position of the parts being shown in full lines when thelamp is in its raised position and in dotted lines when it is at its lowof themast, and Fig. 3 is a front view of the outer end of the arm.

I have shown my improvements in connection with an ordinary mast. It will be apparent, however, that my invention is equally applicable, with slight changes in the details of construction, to lamps suspended from arms projecting from the sides of buildings.

1 represents the mast, 2 the mastarm, and 3 braces and trusses of ordinary construction for imparting strength and rigidity to the mast-arm. The arm is of course made solid with the mast, and at its outer endis provided with a head, 4, which is attached thereto in any suitable manner.

5 is a track, the outer end of which is pivoted to the head, and which is provided at its inner endwith a stop, 6, the purpose of which wilLpresently be explained. This track lies between the pair of braces, (one only being shown,)"which extend from.the mast to the arm, the braces acting as a guide to the track as it is raised and lowered, and also serving to hold it in place when at its raised position. As shown in Fig. 3, the outer end of thetrack is bifurcated, branches thereof being pivoted on opposite sides of the head.

7 isa pulley pivot-ed in the head at the outer end of the arm.

8 indicates curved arms, which are attached to the head and extend inward below the track when in its'raised position, the functions of which will presently be explained. A single bolt, 9, passing through the curved arms, the branches of the track, thehead, and pulley 7, serves to secure these parts in operative position, the curved arms being additionally secured to the head by one or more bolts, as shown, whereby they are prevented from turning.

10 indicates an electric lamp of any' construction, and 11 a cross-piece which serves to engage arms 8 should the suspending-cord be broken, as will be more fully explained.

12 indicates a pulley, which' is journaled on 'cross-piece11, and is adapted to travel upon track 5, and. from which the lamp is suspended.

14 is aweight which serves asa counter-balby 16, passes through the mast, then over a pulley, 20, upon the opposite side thereof, and

is attached to the inner endof track 5. As it is convenient in use to have cords depending from the inner end of track 5, and from the weight, as a means for operating the device, I preferably extend cord 16 downwardand attach its other end also to the weight, as is clearly shown inFig. 1. p

21 indicates the currentwires,which, how ever, for the sake of clearness, I have only shown as extending from the pole to the lamp. These current-wires form no portion of my invention, and it will of course be understood that the connections may be made in the ordinary or in any preferred manner. The position assumed by the current-wires when the lamp is in its lowered position is clearly sh own by dotted lines in Fig. 1.

As stated above, the weight is so regulated as to serve as a perfect counter-balance for the lamp-that is to say, when both weight and lamp are in a position half-way between the positions at which they are as shown in full andin dotted lines, each will balance the other. WVhen, therefore, the weight is moved below this position, it will act to carry the lamp to its raised position, and when the weight is raised above this position it will allow the lamp to move to its lowered position. It will of course be apparent that the operations of lowering or raising the lamp may be perfectly and easily controlled by cord 16. Stop 6 at the inner end of the track catches pulley 12 when it has reached its lowest position, and

holds it, thus preventing the lamp from passing off the track.

In order to avoid the possibility of the lamp falling to the ground should either or both of the cords become broken, I have provided curved arms 8, which catch it and hold it by means of cross-piece 11. Should cord 16 be come broken, the inner end of the track would of course drop instantly. It would, however, swing inward between these arms, so that there would be no possibility of the lamp running down the track, as the cross-piece 11 would catch upon these arms 8.

In order to insure that pulley 12 shall always travel down the track as it is lowered, I provide a cord or wire, 22, which is attached at one end to cross-piece 11, and which extends along over the track, between the supportingbraces, through stop 6, which is preferably provided with a pulley, (not shown,) and the inner end of which is attached to the mast. There can be no trouble of this kind unless the track is icy. This danger is wholly avoided, however, by the use of cord or wire 22. As the inner end of the track drops down, the cord or wire is necessarilypulled down also, it sliding freely through the stop, thus compelling pulley 12, from which the lamp is suspended, to travel down the track.

It will ofcourse be understood that the details of construction may be considerably varied without departing from the spirit of my invention.

I claim- 1. A rigid arm and a track pivoted at the outer end thereof, in combination with the weight and two cords extending upward therefrom, one of which is attached to a pulley, from which the lamp is suspended, and which is adapted to travel upon the track, the other passing to the inner end of said track, whereby when said weight is raised the inner end of the track is permitted to fall and the lamp to move downward thereon.

2. The rigid arm and a track pivoted at the outer end thereof, in combination with pulley 12, which is adapted to travel on said track, and from which the lamp is suspended,weight 14., and two cords passing upward vfrom said weight, one of which is attached to said pulley and the other to the inner end of the track. 3. The arm, track 5, pivoted at the outer end thereof and having at its inner end a stop, and a pulley adapted to travel on said track, in combination with a weight and two cords passing upward therefrom, one of which extends to said pulley, the other to theinner end of the track.

4. The arm, track 5, pivoted at the outer end thereof, and pulley 12, adapted to travel on said track, and from which the lamp is suspended, in combination with a cord, 15,

extending upward from the weight, then along the arm to the lamp, and a cord, 16, which extends upward, is attached to the inner end of thetrack, and then extends do wnward again, and is a second time attached to the weight.

5. The arm, track 5, pivoted thereto, and a pulley, 12, adapted to travel on said track, in combination with the weight, cord 15, which passes from said weight over pulley 17, through the arm, then over pulley 7, and to pulley 12,

and cord 16, which extends over pulleys 17 and 20, is attached to the inner end of the track, and then extends downward and is a second time attached to the weight.

" 6. The arm, the track pivoted at the outer end thereof, and pulley 12, adapted to travel on said track, in combinationwith curved arms 8, an electric lamp having a cross-piece, 11, weight 14, and cords extending upward therefrom, one of which is secured to pulley 12 and the other to the inner end of the track, whereby, should either cord break, the lamp will be caught by the engagement of the crosspiece with arms 8.

7. The arm having at its outer end head 4, the track pivoted to said head, and arms 8, secured thereto, in combination with the lamp, pulley 12, the cross-piece 11, weight 14, and cords 15 and 16.

8. The arm having head 4, the track pivoted thereto and-having a stop, 6, at its outer end, in combination with pulley 12, adapted to travel on said track and to carry a lamp, a weight adapted to counterbalance said lamp,

and cords 15 and 16, one of which passes from whose inner end is attached to the mast,where- 10 the weight to said lamp, the other passing to by said pulley is caused to travel down the the inner end of said track, then downward to track as it is lowered.

the weight again. I In testimony whereof I affix my signature in 5 9. The arm, the track pivoted thereto and presence of two witnesses.

having stop 6 at its free end, and pulley 12, THADDEUS B. KEELER.

from which the lamp is suspended, in combi- Witnesses:

nation with a cord, 22, extending from the A. M. WOOSTER,

journal of said pulley through stop 6, and CORA E. RUGGLES. 

